Condenser - Johnson Controls FRICK QUANTUM HD Operation

ACCESSING:
DESCRIPTION: If Condenser is enabled, this screen allows
the end user to enter and view the basic operating pa-
rameters related to condenser digital operation.
Wet Bulb Strategy
The Quantum™ HD Compressor control panel
provides a Wet Bulb control strategy which has
the ability to run a condenser based on current
atmospheric conditions by sensing the outdoor
air temperature and humidity. This technique,
which is sometimes referred to as fl oating head
pressure, provides the ability to run a refrigera-
tion system at the lowest attainablr head pres-
sure. Traditional condenser control uses a fi xed
head pressure that does not change with weather
conditions or system load. However studies have
found that allowing the condenser/head pressure
to fl oat will result in energy savings. These sav-
ings result from the compressor not working as
hard. While the condenser may use more energy
to achieve a lower head pressure, the reduction
in energy consumption by the compressor is sig-
nifi cantly greater, providing an overall savings.
The Wet Bulb control utilizes a humidity sensor
along with a standard (dry bulb) temperature
sensor. These values are combined to calculate
a Wet Bulb temperature. The Wet Bulb Approach
temperature is then added to the calculated Wet
Bulb temperature. The Approach temperature
sets how close the condenser will run to the
QUANTUM™ HD COMPRESSOR CONTROL PANEL
OPERATION
CONFIGURATION

Condenser

Condenser
Web Bulb temperature and will be determined
by the condenser and system design. Finally, the
Control temperature (which is the sum of the
Wet Bulb Temperature and the Approach Tem-
perature) is converted to the saturated vapor
pressure which in turn becomes the condenser
control pressure. A minimum condensing pres-
sure setpoint specifi es the lowest permissible
condenser control pressure, and is often dictat-
ed by expansion valves or hot gas requirements.
The following setpoints and pop-up menus are provided:
CONDENSER
Condenser
• Disabled
•
• Enabled
[Condenser Control Setpoint] – This is the val-
ue that the Condenser will be controlled to.
System Discharge Pressure – The current Sys-
tem Discharge Pressure is shown here.
VFD Output – This value represents the amount
of VFD output to the condenser fan(s).
Output A - D - The four digital output modules
090.040-O (MAR 12)
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